The three battery types currently used most frequently in laptops are lithium ion, nickel cadmium, and nickel metal hydride.
Nickel Cadmium (Ni-Cd)
Nickel Cadmium (Ni-Cd) batteries were the industry standard for many years, but they are no longer used by new computers because they are outdated technology. They are cumbersome and very susceptible to the “memory effect.” When a NiCd battery is recharged after being partially discharged, it “remembers” the previous charge and resumes it the following time it is used. The memory effect, which is brought on by the compounds in your battery crystallizing, might permanently shorten or even render your battery worthless. You should fully discharge the battery and then recharge it once more at least once every few weeks to prevent it. This battery needs to always be recycled or disposed of properly because it contains the toxic element cadmium.
The memory effect is a problem with NiCad batteries and to a lesser extent NiMH batteries. Memory Effect describes how a battery will lose the ability to further discharge itself if it is frequently only partially exhausted before recharging. The best way to avoid this circumstance is to regularly fully charge and discharge your battery.
Nickel Metal Hydride (Ni-MH)
Ni-MH batteries are a cadmium-free alternative to NiCad batteries. They need less upkeep and conditioning since they are less susceptible to the memory effect than NiCd. However, they struggle in extremely hot or cold indoor settings. Even though they don’t contain heavy metals and employ less harmful materials, they can’t yet be recycled completely. NiMH batteries have a higher energy density than NiCad batteries, which is another key distinction between the two types of batteries. In other words, a NiMH battery has roughly twice the capacity of a NiCad battery. You will benefit from longer battery life without adding bulk or weight, as a result.
Lithium Ion (Li-ion)
The latest industry standard for portable power is lithium-ion (Li-ion). Lithium-ion batteries have a similar energy output as NiMH batteries but are 20%–35% lighter. Unlike their NiMH and Ni-Cd competitors, they do not notably experience the memory effect. Their products pose no risk to the 0. They need special handling because lithium ignites very easily. Sadly, there are currently very few consumer-based Li-ion battery recycling programs in place.
Although they are not different kinds of batteries, smart batteries are worth highlighting. The internal circuit boards of smart batteries have chips that enable them to interact with the laptop and track battery life, output voltage, and temperature. Due to their higher efficiency, smart batteries typically last 15% longer and also give the computer much more precise “fuel gauge” capabilities to calculate how much battery run time is left before the next recharge is needed.
General Battery Care
The charging process for each of the three types of batteries is different, so even if the battery case looks the same, you cannot simply upgrade to a different battery technology unless your laptop has been pre-configured by the manufacturer to accept more than one type of battery.